Any kind of telescope can do this sort of spectroscopy work. Kornreich often uses the inch telescope at the Palomar Observatory at the California Institute of Technology, but he added that almost any telescope of sufficient size would be adequate. The ideal would be using a telescope in orbit because scattering occurs in Earth's atmosphere from light pollution and also from natural events — even something as simple as a sunset.
The Hubble Space Telescope is one observatory known for this sort of work, Kornreich added. A successor observatory called the James Webb Space Telescope is expected to launch in The challenge, however, is that Hubble is a telescope in high demand — and the same is expected of Webb after its launch.
So the observatories can't spend all of their time estimating galaxy mass. Between different galaxies of the same mass, there could be variances as to the types of stars and the overall mass. Kornreich cautioned this would be very hard to speak about generally, but said that one difference could be looking at elliptical galaxies vs. Elliptical galaxies tend to have more K- and M-type red dwarf stars than spiral galaxies.
Because elliptical galaxies are older, they will have less gas because that was blown away during their evolution. Once a galaxy's mass is determined, the other tricky thing is figuring out how much of that mass is made of stars. Most of the mass will be made up of dark matter , a type of matter that emits no light but which is believed to make up most of the mass of the universe. With much of the remaining "stuff" in the galaxy made up of diffuse gas and dust, Kornreich estimated that about 3 percent of the galaxy's mass will be made up of stars, but that could vary.
Further, the size of the stars itself can greatly vary from something that is the size of our sun, to something dozens of times smaller or bigger. The number of stars is approximately …. This zone is the region around a star where temperatures allow for water - a key ingredient for life - to stay liquid at the surface. The researchers have published details in the journal PNAS.
His UC Berkeley colleague Andrew Howard said the discovery showed that planets like our own were relatively common throughout the Milky Way galaxy. Last week, astronomers announced the discovery of an Earth-sized, rocky planet orbiting its star at a hundredth of the distance between the Earth and the Sun.
Temperatures on this world would reach between 2,C and 2,C, with much of the dayside molten, meaning there would be little chance for life here. But team members cautioned that even finding Earth-sized planets in the habitable - or "Goldilocks" - zones of their stars was no guarantee these worlds would be hospitable to life.
Our galaxy. Are stars more numerous than planets? They might be, but at the same time, our Sun hosts eight planets, so planets might be more numerous. It all depends on circumstance and causality; however, in our galaxy, the Milky Way, there are around billion estimated planets at least. These planets are often called exoplanets , which means planets that orbit other stars, not our star, the Sun. There are also rogue planets, which are planets that have been kicked out of their planetary systems either through a collision or their star dying off, and thus being unable to bound its planets gravitationally.
Some other planets that are located in the Milky Way, and not in our Solar System, are called exoplanets, and here are some of them:. Keplerf — a planet similar to our Earth. Kepler System — a planetary system composed of at least five exoplanets that orbit their star as close as Mercury does with the Sun. Keplerb — also known as a circumbinary planet, which orbits two stars. The star orbited by Pegasi b is quite similar to our Sun.
CoRoT 7b — This planet is known as a super-Earth. It is a rocky planet similar to ours, yet several times bigger. It orbits in the habitable zone of its star. Keplerb — This planet might have all of its surface made out of water, and it is situated in the habitable zone of its parent star. Keplerb — This planet is an Earth-sized exoplanet that is scorched, and many believe it might have a lava ocean on its surface. There are a hundred billion stars in the Milky Way.
Or is it billion? Or billion? The Milky Way is embedded in a clump of dark matter that is far larger and more massive than the galaxy itself. That glue, we now know, is dark matter. The Milky Way is also surrounded by more than ancient groups of stars, some of which are among the oldest in the universe.
Each is crammed with hundreds of thousands of stars. Also hanging around the Milky Way are dozens of satellite galaxies ; most of these are tough to see, but the Small and Large Magellanic Clouds glisten each night in the southern sky. The Milky Way eats galaxies that come too close. At the AAS meeting, the Dark Energy Survey team announced that it had detected 11 more of these streamers , some of which have been given Aboriginal names.
The Milky Way is blowing massive bubbles of extremely hot gas and energetic particles. Scientists studying the deserting swarm say the clouds can act as tracers for the powerful processes that produce the giant Fermi bubbles. All rights reserved. Share Tweet Email. Why it's so hard to treat pain in infants.
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